1. Field of the Invention
The present invention relates generally to tribological testing for head-disk interface areas in computer disk drives, and more particularly but not by way of limitation, to accelerated determination of head and disk performance degradation individually and in combination with high accuracy life expectancy predictions.
2. Brief Description of the Related Art
The science of tribological testing in head-disk assemblies has become more important as the dimensions of magnetic recording have become smaller in the attempt to make magnetic information more compact. Two documents of interest are U.S. Pat. No. 4,532,802 issued Aug. 6, 1985 to C. E. Yeack-Scranton and S. F. Vogel entitled "Apparatus for Analyzing the Interface between a Recording Disk and a Read/Write Head"; and an article by Kawakubo et al. (Hitachi Ltd., Toyko, Japan) entitled "Spherical Pin Sliding Test on Coding Magnetic Recording Disk".
U.S. Pat. No. 4,532,802 teaches a piezoelectric crystal for measuring vertical acceleration of a slider as it moves across a disk. This patent also teaches how to measure vertical acceleration of the slider.
The Kawakubo et al. article teaches a device for measuring frictional force using a spherically lapped wear slider. The slider is constructed of a crystalline material, such as ruby or sapphire.
Up to the present time resolution has not been made as to how to obtain three-dimensional acceleration analysis of a slider in motion contact with a disk. Accelerated testing of real time wear on head-disk components has not been available to provide complete information regarding three-dimensional head-disk interface contact stress.